Polyurethane Foam Infill (PUF)

Polyurethane Foam Infill (PUF) is applied to the joint area of concrete weight coated pipes to provide protection to the welded joint area and to assist with pipe movement over the rollers. PUF material formulations are available to offer specific performance criteria.

The HDPF system develops a rigid, open cell structure. Upon immersion, the open cells will absorb water, thereby increasing in overall density to approximately 1025 kg/m3 (similar to seawater itself). The low-viscosity product formulation of the HDPF system allows “free flow” of chemicals to ensure quick and complete filling of the mold, within the cycle times demanded by today’s offshore laybarge operations.

PIH has developed equipment and processes for the efficient installation of PUF and provides services to pipe lay contractors around the world.

PUF Features and Benefits

  • Commercially attractive
  • Rapid cycle times
  • Reusable or expendable/disposable (metallic or plastic) mold systems
  • Compact, reliable application equipment
  • Compatibility with all conventional anti-corrosion field joint coating systems
  • ODP: Zero category formulation
  • No solvents required: All equipment is air-/water-purged
  • A range of foam densities is available
  • Raw material storage requires only 16 to 20% of that needed for marine mastic
  • Solutions include prefabricated PUF half shells

PUF Application

  1. Surface preparation
  2. Application of corrosion protection system (3-layer systems or multi-layer systems)
  3. Locate “mold”
  4. Pump PUF material into “mold”

Following application of the corrosion protection system the PU foam is applied.

A mold is located at the joint area and the PUF material is pumped into the mold at the required rates.

The infilling system can incorporate reusable or disposable molds. Reusable molding is used in conjunction with a cardboard fiber liner to create a superior high-strength composite skin. This system will allow the de-molded field joint to pass over the laybarge rollers and “stinger” without damage due to the fiber liner becoming embedded in the surface of the foam, creating a protective outer skin to the joint area.

Disposable plastic or metal molds can be used as required by environmental and operational demands. 

The PIH pumping modules are neat and compact, consisting of two holding tanks, small pumping equipment, and dispensing hoses and nozzles. 

  Standard High Capacity
Pipe Diameter 2"-56" 2"-56"
Voltage - 240 v
Current - 16 A
Air Consumption 100 CFM @ 100 psi 100 CFM @ 100 psi
Weight 185 Kg 4000 Kg
Dimensions (L x W x H) 850 x 770 x 830mm (excluding day tanks) 6060 x 2400 x 2400mm
Pumping Rates 60 Kg/min 180 Kg/min